﻿using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;

/// <summary>
/// container function:
/// -CutFiveChar
/// </summary>
public class FunctionSupport
{
	public FunctionSupport()
	{
        
	}
    public static string CutFiveChar(string s)
    {
        Random rand = new Random();
        int k = rand.Next(0, s.Length - 5);
        string l = s.Substring(k, 5);
        return l;
    }
    public static string LayDuoiFile(string s)
    {
        return s.Substring(s.Length - 4, 4);
    }
   
}